Great advice Martin. I wanted a watch version because I don't like the idea of a strap. I would be using it when I start back at the gym, because their machines aren't reliable. Mainly want to use it for calorie counting.
Can anyone reccomend a good watch version that doesn't cost an arm and a leg? Also one that works well, because the reviews online are rubbish.
HRM use an alogrithm to calculate calories so make sure you can enter gender, age and your weight. this will be more accurate. It works ok for aerobic exercise, as muscles work 'consistently'.
The challenge with weights or kettlebell is that you use different muscle groups - a bicep curl uses a small muscle but your heart responds in a similar manner as it would for say a lunge which uses more and larger muscle. The bicep only uses a fraction of the energy that your bum and legs do in a lunge. Then you also have with weight based exercise the effect where if you overloaded the muscle it will recover over the next 24-48hrs using calories which wont be counted. This effect doesnt happen to the same effect with aerobic exercise.
Its still a useful gauge and working in the heart rate ranges is really beneficial